Pantograph device



June 18, 1946. QCHSNER 2,402,438

PANTOGRAPH DEVICE Filed March 27, 1942 5 SheeFs-Sheet 1 June 18, 1946. QCHSNER 2,402,438

PANTOGRAPH DEVICE Filed March 27, 1942 3 SheetsSheet 2 June 18, 1946. bc s 2,402,438

PANTOGRAPH DEVICE Filed March 27, 1942 s Sheets-Sheet 3 Patented June 18, 1946 UNITED STATES PATENT OFFICE Application March 27, 1942, Serial No. 438,507

.results with a simple, inexpensive, and readily installed mechanism which selectively replaces manual grounding. 1

With the above and other objects and advantageous features in view, the invention consists of a novel arrangement of parts more specifically disclosed in the detailed description following, in

2 Claims. 178-65) conjunction with the accompanying drawings,

and more specifically defined in the claims appended thereto.

In the drawings:

Fig. l is a side elevation of a panto'graph machine equipped with the novel grounding mechanism;

Fig. 2 is a side view thereof;

Fig. 3 is a sectional detail on the line 3-3 of Figs. 1 and 2;

Fig. 8 is a schematic wiring diagram for the electrical control wiring.

The grounding of areas for receiving printing dyes has heretofore been manually controlled.

A master plate'is prepared from the original design, and is mounted on a pantograph engraving machine; the operator traces the design from the master plate by means of diamond pointed tools which scribe the operators work on the surface of the printing roller, cutting through a surface layer of acid resisting varnish. Each printing area is thus ruled with a number of layer, and subsequent etching produces a print- I have provided an automatic mechanism for ruling the grounding lines. To this end, I provide an electric eye operating on the principle of light change and light reflection, and a light control by painting such surfaces of the master plate as it is desired to ground, with a light reflecting paint, the other portions of the master plate being dark and non-reflecting. 4

I attach a scanning head, comprising the electric eye and its light source, to the upper carriage of the pantograph, in lieu of the operator's tracing handle and point. The lower carriage of the pantograph is utilized to move the scanning head from one end of the master plate to the other. When the scanning head is activated by a light change on the master plate, the power from the scanning head is amplified by means of a photo-electric relay to operate a control bar for lifting and for dropping the diamond scribing tools onto and off the roller.

Referring to the drawings, the machine comprises a base in having spaced pai'alleltracks Ii f Y mounted thereon. A lower carriage i2 is pro vided with rollers or wheels it which 'ride on the tracks ii, and also has upper spaced parallel tracks it which are positioned at right angles to the tracks Ii. or wheels l8 which ride on the tracks ll, whereby the combination of upper and lower carriages proand idling pulleys 22, the ends of the belt being secured to fixed posts 23 mounted on opposite sides of the base l0. When the lower carriage is driven backward or forward on the tracks I I by belt A for power operation, or by hand for scribing the outline, the belt ll moves over the pulley 20 and this produces rotation of the shaft l8 and the printing roller l9. r

ing area having a series of depressions of predetermined depth, dependent on the fineness of the ruling. The depressions provide a series of dams for holding the printing dye, the separating 1 boundary lines supporting the doctor blade; an

.lower bearings 20. Oneor more diamond carryto' the lower shaft 28, each having scribing points ll' extending upwardly: a counter weight 38 may An upper carriage I! has rollers,

. 3 be adJustably positioned on each bar II to swing the points 82 into contact with the roller H.

An arm I4 is fixed to the upper carriage l5 and extends downwardly towards the base it and a master plate 35, bearing the design, which is mounted on thebase. The operator moves the arm, which normally carries a tracing handle, around the design on the master plate and the movement of the upper and lower carriages turns and moves the roller l8 accordingly and traces the same outline on the roller l9 beneath each. scribing point.

To scribe the design with the necessary spaced lines, the design on the master plate is painted with a light reflecting paint, and the tracing handle is replaced with a scanning head 38 which includes a source of light "A and also a photoelectric eye "3 adapted to pick up the light reflected from the painted portion of the design.

Mounted on the lower carriage is an electric motor 31 coupled to a screw 38 mounted beneath the upper carriage II. A nut 39 rides on the screw 18 and is fixed to the upper carriage 15, as by removable pin 40. Rotation of the screw thus moves the carriage I! back and forth, depending on the direction of rotation, across the carriage I 2, the direction of rotation of the motor being controlled by limit switches 4| and 42 which are adjustable for size of plate and operate when they are engaged by the nut 39. The upper and lower carriages thus provide the pantograph with linear and crossmovements.

Contact between the diamond points and 32 and the roller I! is controlled by upper and lower tipping bars 43 and 44, which are pivotally mounted on the frames 24, the tipping bars 43 and 44 being linked to a pivoted bar mounted at the rear of the upper carriage. A solenoid 4B is mounted above the bar 45 and loosely attached thereto by means of a strap 41, and is operated by electrical impulses from the scanning head 36. Referring to Fig. 3, the links 43a and 440. operating the tipping bars 43 and 44 are mounted on each side of the pivot of the bar 45 so that downward movement of the bar 45 causes the tipping bars to release the diamond points and permit them to contact the surface of the roller I.

With the machine set up as hereinabove described, when the motor 31 moves upper carriage II alongthe iemrth of the screw 38, the arm 14 passes the scanning head 38 over the. master plate 88. As the eye reaches the light reflecting painted portion of the design, an electric impulse is relayed to the solenoid 44 to thus cause the diamond Points to scribe lines on the roller 19 as hereinabove described. As the eyeleaves the painted portion of the design. the reflection ceases, the electric impulse is shut off, and the solenoid operates the tipping bars 43 and 44 to shift the diamond points away from the roller l8. When the upper carriage ll reaches the desired limit of travel, it operates the limit switch 42 to reverse the motor 11, the scanning head 38 being shut ofl, whereupon the upper carriage returns to the beginnhigof its movement without operating the diamond points over the inscribed lines. Upon and 5, which is preferably mounted on the arm 34. A support 4! is positioned on the arm I l and is provided with spaced arms in which a shaft ii is rotatably Journalled. A spool 52 is keyed to the shaft between the arms 50 and an indexing wheel 53 is keyed to the forward end of the shaft. The indexing wheel 5! is provided with a plurality of rows of spaced openings 84, the spacing of the openings controlling the spacing of the inscribed lines as hereinafter described.

Mounted above the indexing wheel 53 is a. solenoid operated pin 80 adapted to selectively enter the spaced openings 84 on the wheel. A post BI is mounted. on the lower carriage adjacent the path of return movement of the arm 34 and indexing unit 48 and has a contact ii at its upper end adapted to be engaged by a spring contact 63 on the solenoid. As the arm 34 reaches the end of its return movement, the contact 83 brushes over the contact 82 and thus actuates the solenoid to lift the pin 80 out of its opening.

A spring pressed friction bar 64 extends laterally from the post Bl to frictionally engage the lower periphery of the wheel I53 prior to engagement of the contacts 82 and 63. As the arm 34 approaches the end of its return movement, the bar 84 frictionally engages the wheel 53 to rotate it, but seating of the pin 80 in the opening 54 prevents this rotation until the pin 60 is lifted by the solenoid, whereupon the wheel 53 turns, whereby the contact 63 leaves the contact 82, the solenoid releases and the pin ill drops into the next opening 54.

Turning movement of the wheel 53 causes the spool 52 to wind or unwind the wire 51 which is connected to the standard indexing mechanism, thereby causing the lower carriage I! to move a predetermined distance. This produces a corresponding turning of the roller ii to provide the necessary spacing for the next ground line; the action is repeated at the end of each return movement of the lower carriage until the entire design has been inscribed.

Although I have described the invention as embodied in a pantograph machine for scribing printing rollers, it is obvious that the invention may be readily applied to other uses, as for example the reproduction of dots and dashes on printing plates by means of wire photo impulses, to thus produce printing plates directly. in quantity if desired. Other uses will be readily apparent to one skilled in the art.

Changes in the size, shape and arrangement of I the parts, and in the manner of controlling the a pantograph having upper and lower carriages for obtaining linear and cross movements, an electriceye mounted on the upper carriage, means for moving said carriages, means for reversing the movement of said carriages, limit switches for reversing the movement of the lower carriage, means for indexing the upper carriage, means for turning said printing roller in correspondence with movement of the cross movement carriage, scribing mechanism, means for man ually moving said scribing mechanism to obtain a scribed outline of the painted design, and means thereon of different light reflecting qualitiestrom' the background, a pantograph having two vcarriages for obtaining movements at right angles to each other, an electric eye mounted on said carriages for movement in any direction, means for moving said carriages, scribing mechanism,

means for turning said printing roller in correspondence with movements of one of saidcarriages, means for moving said scribing mechanism longitudinally of said roller by movement of the other of said carriages, means for manually moving said scribing mechanism to obtain a. scribed outline of the design, and means responsive to variations in reflection from the design to said electric eye for controlling said scribing mechanism to scribe grounding lines on said.

roller.

ARNOLD G. OCHSNER. 

